Health Maintenance Organization (HMO) and Medicare

A Health Maintenance Organization or (HMO) is a Medicare Health Plan that is available throughout most of the United States. An HMO Plan must cover all Medicare Part A and Part B health care. Some HMOs cover extra benefits, like additional days in the hospital.

With most HMOs, you can only go to doctors, specialists, or hospitals that are on the plan's list except in the case of an emergency. There is a possibility that your costs may be lower than in the Original Medicare Plan.

A majority of the HMOs require that you select a primary care physician (PCP). This doctor acts as a "gatekeeper" to direct your access to medical services. PCPs are usually family doctors, pediatricians, internists, or general practitioners.

Unless it is a medical emergency, you need a referral from your PCP in order to see a specialist or other doctor. The gatekeeper cannot authorize that referral unless the HMO guidelines consider the referral necessary.